Enhanced retry count for uplink multi-user transmission

ABSTRACT

This disclosure describes systems, methods, and devices related to enhanced retry count for an uplink (UL) multi-user (MU) transmission. A device may identify a trigger frame received from a first device on a wireless communication channel. The device may determine a quality of service counter associated with an access category. The device may cause to send a frame to the first device based at least in part on the trigger frame. The device may determine an error condition associated with the frame. The device may refrain from incrementing the quality of service counter based on the error condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/349,345 filed Jun. 13, 2016, the disclosure of which is incorporatedherein by reference as if set forth in full.

TECHNICAL FIELD

This disclosure generally relates to systems and methods for wirelesscommunications and, more particularly, to an enhanced retry count foruplink multi-user transmission.

BACKGROUND

Efficient use of the resources of a wireless local area network (WLAN)is important to provide bandwidth and acceptable response times to theusers of the WLAN. However, often there are many devices trying to sharethe same resources, and some devices may be limited by the communicationprotocol they use or by their hardware bandwidth. Moreover, wirelessdevices may need to operate with both newer protocols and with legacydevice protocols

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example and notlimitation in the figures of the accompanying drawings, in which likereferences indicate similar elements and in which:

FIG. 1 illustrates a wireless local area network (WLAN), in accordancewith one or more example embodiments of the present disclosure.

FIG. 2 illustrates a schematic diagram of uplink (UL) multi-user (MU)transmissions, in accordance with one or more example embodiments of thepresent disclosure.

FIG. 3 illustrates a schematic diagram of transmission error detectionand a retry counter, in accordance with one or more example embodimentsof the present disclosure.

FIG. 4 illustrates a schematic diagram of an enhanced retry count for aUL MU transmission system, in accordance with one or more exampleembodiments of the present disclosure.

FIG. 5 illustrates a flow diagram of an illustrative process for anenhanced retry count for a UL MU transmission system, in accordance withone or more example embodiments of the present disclosure.

FIG. 6 illustrates a flow diagram of an illustrative process for anenhanced retry count for a UL MU transmission system, in accordance withone or more example embodiments of the present disclosure.

FIG. 7 illustrates a functional diagram of an example communicationstation that may be suitable for use as a user device, in accordancewith one or more example embodiments of the present disclosure.

FIG. 8 illustrates a block diagram of an example machine upon which anyof one or more techniques (e.g., methods) may be performed, inaccordance with one or more example embodiments of the presentdisclosure.

DESCRIPTION

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

A quality of service (QoS) design in IEEE 802.11ax includes associatingpackets with QoS values that are specific to access categories (ACs). Inthat case, channel access through contention involves assigningcontention window (CW) values that are dependent on the AC in order toprovide an advantage for higher priority frames (e.g., voice versusvideo). Currently, there are four ACs: voice (VO), video (VI), besteffort (BE), and background (BK) for transmitting packets through mediumaccess. In order to contend for access of a channel, for each AC, astation (STA) may determine a channel access delay that includes arandom backoff timer that is associated with a contention window. TheSTA begins decrementing the random backoff timer by one for every slottime that passes.

If another STA begins transmitting before its timer has reached zero,the STA defers access until the medium is available again, at which timeit continues decrementing the timer from where it previously left off.Once the timer reaches zero, the STA is allowed to transmit its frame.If a collision occurs, or due to noise, collisions, or interferences, noacknowledgment of the frame will be received by the STA, and the STAwill increment its retry counter and increase its CW up to a maximumcontention window (CWmax). The STA would then select a new randombackoff timer between the value of 0 and CW, using the new CW range, andproceed as before. However, if the retry counter reaches the limit, theCW is reset to CWmin, and the retry counter is set to 0. Therefore, theSTA will have a shorter channel access time during the next channelaccess attempt and will take precedence over other STAs. In effect, thismay create an unintentional increase in priority to STAs that weretriggered by the access point and had transmission failures.

In one embodiment, an enhanced retry count for an uplink (UL) multi-user(MU) transmission system may identify a trigger frame received from adevice, such as an access point (AP) on a wireless communicationchannel. The AP may be in a multi-user multiple-input multiple-output(MU-MIMO) communication with multiple STAs. The AP may send a triggerframe to trigger data transmission from multiple STAs simultaneouslyusing orthogonal frequency division multiple access (OFDMA) or MIMO.

In one embodiment, the enhanced retry count for the UL MU transmissionsystem may cause to send a frame to the AP based at least in part on thetrigger frame. However, the frame may fail to reach the AP due to anerror condition such as noise, interference, collision, or any otherconditions that may prevent the frame from reaching the AP. The STAwould determine the error condition based on a failure to receive anacknowledgment from the AP after sending the frame to the AP.

In one embodiment, the enhanced retry count for the UL MU transmissionsystem may determine the retry counters to be at least one of a qualityof service short retry counter (QSRC), a quality of service long retrycounter (QLRC), a quality of service long drop-eligible retry counter(QLDRC), or a quality of service short drop-eligible retry counter(QSDRC).

In one embodiment, the enhanced retry count for the UL MU transmissionsystem may determine a retry counter limit, which may be determinedbased at least in part on the type of retry counter (e.g., QSRC, QLRC,QLDRC, or QSDRC). For example, the retry limit for QSRC is designated asdot11ShortRetryLimit, and the retry limit for the dot11ShortRetryLimitis designated as dot11LongRetryLimit based at least in part on IEEE802.11 standards and may be determined by higher layers.

In one embodiment, the enhanced retry count for the UL MU transmissionsystem may determine whether a dot11RobustAVStreamingImplemented valueis set to true or false. The dot11RobustAVStreamingImplemented value maybe determined by higher layers. If the dot11RobustAVStreamingImplementedvalue is determined to be false, then an STA may refrain from updatingits retry counters (e.g., QSRC or QLRC) when the data transmission forthe corresponding AC solicited by the AP through a trigger frame fails.If dot11RobustAVStreamingImplemented is true, then the STA may refrainfrom updating its retry counters (e.g., QSDRC, or QLDRC) when the datatransmission for the corresponding AC solicited by the AP through thetrigger frame fails. It is understood that the above descriptions arefor purposes of illustration and are not meant to be limiting.

FIG. 1 illustrates a WLAN 100 in accordance with some embodiments. TheWLAN 100 may comprise a basis service set (BSS) that may include amaster station 102 which may be an AP, a plurality of high-efficiency(HE) (e.g., IEEE 802.11ax) stations 104, and a plurality of legacy(e.g., IEEE 802.11n/ac) devices 106.

The master station 102 may be an AP using one of the IEEE 802.11protocols to transmit and receive. The master station 102 may be a basestation. The master station 102 may use other communications protocolsas well as the IEEE 802.11 protocol. The IEEE 802.11 protocol may beIEEE 802.11ax. The IEEE 802.11 protocol may include using orthogonalfrequency division multiple access (OFDMA), time division multipleaccess (TDMA), and/or code division multiple access (CDMA). The IEEE802.11 protocol may include a multiple access technique. For example,the IEEE 802.11 protocol may include space-division multiple access(SDMA) and/or multiple-user multiple-input multiple-output (MU-MIMO).The master station 102 and/or the HE station 104 may use one or both ofMU-MIMO and OFDMA. There may be more than one master station 102 that ispart of an extended service set (ESS). A controller (not illustrated)may store information that is common to the more than one master station102. The controller may have access to an external network such as theInternet.

The legacy devices 106 may operate in accordance with one or more ofIEEE 802.11 a/b/g/n/ac/ad/af/ah/aj, or another legacy wirelesscommunication standard. The legacy devices 106 may be STAs or IEEE802.11 STAs.

The HE stations 104 may be wireless transmit and receive devices such ascellular telephones, smart telephones, handheld wireless devices,wireless glasses, wireless watches, wireless personal devices, tablets,or another device that may be transmitting and receiving using the IEEE802.11 protocol such as IEEE 802.11ax or another wireless protocol suchas IEEE 802.11az. In some embodiments, the HE stations 104, the masterstation 102, and/or the legacy devices 106 may be termed wirelessdevices. In some embodiments, the HE station 104 may be a “group owner”(GO) for peer-to-peer modes of operation where the HE station 104 mayperform some operations of a master station 102.

The master station 102 may communicate with the legacy devices 106 inaccordance with legacy IEEE 802.11 communication techniques. In exampleembodiments, the master station 102 may also be configured tocommunicate with the HE stations 104 in accordance with legacy IEEE802.11 communication techniques.

The HE stations 104, the master station 102, and/or the legacy devices106 may be any addressable unit. It should be noted that any addressableunit may be a station (STA). An STA may take on multiple distinctcharacteristics, each of which shapes its function. For example, asingle addressable unit might simultaneously be a portable STA, aquality-of-service (QoS) STA, a dependent STA, and a hidden STA. The HEstations 104, the master station 102, and/or the legacy devices 106 maybe STAs. The HE stations 104, the master station 102, and/or the legacydevices 106 may operate as a personal basic service set (PBSS) controlpoint/access point (PCP/AP). The HE stations 104, the master station102, and/or the legacy devices 106 may include any suitableprocessor-driven device including, but not limited to, a mobile deviceor a non-mobile device, e.g., a static device. For example, the HEstations 104, the master station 102, and/or the legacy devices 106 mayinclude a user equipment (UE), a station (STA), an access point (AP), asoftware enabled AP (SoftAP), a personal computer (PC), a wearablewireless device (e.g., bracelet, watch, glasses, ring, etc.), a desktopcomputer, a mobile computer, a laptop computer, an ultrabook™ computer,a notebook computer, a tablet computer, a server computer, a handheldcomputer, a handheld device, an internet of things (IoT) device, asensor device, a PDA device, a handheld PDA device, an on-board device,an off-board device, a hybrid device (e.g., combining cellular phonefunctionalities with PDA device functionalities), a consumer device, avehicular device, a non-vehicular device, a mobile or portable device, anon-mobile or non-portable device, a mobile phone, a cellular telephone,a PCS device, a PDA device which incorporates a wireless communicationdevice, a mobile or portable GPS device, a DVB device, a relativelysmall computing device, a non-desktop computer, a “carry small livelarge” (CSLL) device, an ultra mobile device (UMD), an ultra mobile PC(UMPC), a mobile internet device (MID), an “origami” device or computingdevice, a device that supports dynamically composable computing (DCC), acontext-aware device, a video device, an audio device, an A/V device, aset-top box (STB), a blu-ray disc (BD) player, a BD recorder, a digitalvideo disc (DVD) player, a high definition (HD) DVD player, a DVDrecorder, a HD DVD recorder, a personal video recorder (PVR), abroadcast HD receiver, a video source, an audio source, a video sink, anaudio sink, a stereo tuner, a broadcast radio receiver, a flat paneldisplay, a personal media player (PMP), a digital video camera (DVC), adigital audio player, a speaker, an audio receiver, an audio amplifier,a gaming device, a data source, a data sink, a digital still camera(DSC), a media player, a smartphone, a television, a music player, orthe like. Other devices, including smart devices such as lamps, climatecontrol, car components, household components, appliances, etc., mayalso be included in this list.

Any of the HE stations 104, the master station 102, and/or the legacydevices 106 may be configured to communicate with each other via one ormore communications networks wirelessly or wired. The HE stations 104and/or the legacy devices 106 may also communicate peer-to-peer ordirectly with each other with or without the master station 102. Any ofthe communications networks may include, but are not limited to, any oneof a combination of different types of suitable communications networkssuch as, for example, broadcasting networks, cable networks, publicnetworks (e.g., the Internet), private networks, wireless networks,cellular networks, or any other suitable private and/or public networks.Further, any of the communications networks may have any suitablecommunication range associated therewith and may include, for example,global networks (e.g., the Internet), metropolitan area networks (MANs),wide area networks (WANs), local area networks (LANs), or personal areanetworks (PANs). In addition, any of the communications networks mayinclude any type of medium over which network traffic may be carriedincluding, but not limited to, coaxial cable, twisted-pair wire, opticalfiber, a hybrid fiber coaxial (HFC) medium, microwave terrestrialtransceivers, radio frequency communication mediums, white spacecommunication mediums, ultra-high frequency communication mediums,satellite communication mediums, or any combination thereof.

Any of the HE stations 104, the master station 102, and/or the legacydevices 106 may include one or more communications antennas. The one ormore communications antennas may be any suitable type of antennascorresponding to the communications protocols used by the HE stations104, the master station 102, and/or the legacy devices 106. Somenon-limiting examples of suitable communications antennas include Wi-Fiantennas, Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards compatible antennas, directional antennas,non-directional antennas, dipole antennas, folded dipole antennas, patchantennas, multiple-input multiple-output (MIMO) antennas,omnidirectional antennas, quasi-omnidirectional antennas, or the like.The one or more communications antennas may be communicatively coupledto a radio component to transmit and/or receive signals, such ascommunications signals to and/or from the HE stations 104, the masterstation 102, and/or the legacy devices 106.

MIMO beamforming in a wireless network may be accomplished using RFbeamforming and/or digital beamforming. In some embodiments, inperforming a given MIMO transmission, the HE stations 104, the masterstation 102, and/or the legacy devices 106 may be configured to use allor a subset of its one or more communications antennas to perform MIMObeamforming.

Any of the HE stations 104, the master station 102, and/or the legacydevices 106 may include any suitable radio and/or transceiver fortransmitting and/or receiving radio frequency (RF) signals in thebandwidth and/or channels corresponding to the communications protocolsutilized by any of the HE stations 104, the master station 102, and/orthe legacy devices 106 to communicate with each other. The radiocomponents may include hardware and/or software to modulate and/ordemodulate communications signals according to pre-establishedtransmission protocols. The radio components may further have hardwareand/or software instructions to communicate via one or more Wi-Fi and/orWi-Fi direct protocols, as standardized by the Institute of Electricaland Electronics Engineers (IEEE) 802.11 standards. In certain exampleembodiments, the radio component, in cooperation with the communicationsantennas, may be configured to communicate via 2.4 GHz channels (e.g.,802.11b, 802.11g, 802.11n, 802.11ax), 5 GHz channels (e.g., 802.11n,802.11ac, 802.11ax), or 60 GHz channels (e.g., 802.11ad). In someembodiments, non-Wi-Fi protocols may be used for communications betweendevices, such as Bluetooth, dedicated short-range communication (DSRC),Ultra-High Frequency (UHF) (e.g., IEEE 802.11af, IEEE 802.22), whiteband frequency (e.g., white spaces), or other packetized radiocommunications. The radio component may include any known receiver andbaseband suitable for communicating via the communications protocols.The radio component may further include a low noise amplifier (LNA),additional signal amplifiers, an analog-to-digital (A/D) converter, oneor more buffers, and a digital baseband.

Typically, when a medium access control (MAC) service data unit (MSDU)arrives from an upper layer to the MAC layer of a device, the MSDU mayfirst be mapped to one of four defined ACs based at least in part on itsuser priority. These four ACs include, in descending priority order, avoice (VO) access category, a video (VI) access category, a best effort(BE) access category, and a background (BK) access category. The MSDU isthen routed to a transmit queue corresponding to the AC to which theMSDU has been mapped. Each such transmit queue may have a correspondingenhanced distributed channel access (EDCA) function (EDCAF), which maydefine a backoff window size, an arbitration interframe space (AIFS),and a transmission opportunity (TXOP) length for all MSDUs in thecorresponding AC. An internal collision resolution scheme may resolveconflicts between the EDCAFs of different queues, and may, for example,allow an MSDU from a higher-priority queue to access the channel anddefer an MSDU from a lower-priority queue when the two queues havebackoff timers that expire at substantially the same time.

In example embodiments, the HE station 104 and/or the master station 102are configured to perform the methods and operations herein described inconjunction with FIGS. 1-6.

In some embodiments, an HE frame may be configurable to have the samebandwidth as a channel. The bandwidth of a channel may be 20 MHz, 40MHz, 80 MHz, 160 MHz, or 320 MHz contiguous bandwidths or an 80+80 MHz(160 MHz) non-contiguous bandwidth. In some embodiments, the bandwidthof a channel may be 1 MHz, 1.25 MHz, 2.03 MHz, 2.5 MHz, 5 MHz and 10MHz, or a combination thereof. Another bandwidth that is less or equalto the available bandwidth may also be used. In some embodiments, thebandwidth of the channels may be based on a number of activesubcarriers. In some embodiments the bandwidth of the channels aremultiples of 26 (e.g., 26, 52, 104, etc.) active subcarriers or tonesthat are spaced by 20 MHz. In some embodiments, the bandwidth of thechannels are 26, 52, 104, 242, etc., active data subcarriers or tonesthat are spaced 20 MHz apart. In some embodiments, the bandwidth of thechannels is 256 tones spaced by 20 MHz. In some embodiments, a 20 MHzchannel may comprise 256 tones for a 256 point Fast Fourier Transform(FFT). In some embodiments, a different number of tones are used.

An HE frame may be configured for transmitting a number of spatialstreams, which may be in accordance with MU-MIMO.

In some embodiments, an HE frame may be configured for transmitting inaccordance with one or both of OFDMA and MU-MIMO. In other embodiments,the master station 102, the HE station 104, and/or the legacy device 106may also implement different technologies such as code division multipleaccess (CDMA) 2000, CDMA 2000 1×, CDMA 2000 Evolution-Data Optimized(EV-DO), Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95),Interim Standard 856 (IS-856), Long Term Evolution (LTE), Global Systemfor Mobile Communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), IEEE 802.16 (i.e., Worldwide Interoperabilityfor Microwave Access (WiMAX)), BlueTooth®, WiMAX, WiGig, or othertechnologies.

Some embodiments relate to HE communications. In accordance with someIEEE 802.11ax embodiments, a master station 102 may operate as a masterstation which may be arranged to contend for a wireless medium (e.g.,during a contention period) to receive exclusive control of the mediumfor an HE control period. In some embodiments, the HE control period maybe termed a transmission opportunity (TXOP). The master station 102 maytransmit an HE master-sync transmission, which may be a trigger frame orHE control, and schedule transmission at the beginning of the HE controlperiod. The master station 102 may transmit a time duration of the TXOPand channel information. During the HE control period, the HE stations104 may communicate with the master station 102 in accordance with anon-contention-based multiple access technique such as OFDMA and/orMU-MIMO. This is unlike conventional WLAN communications in whichdevices communicate in accordance with a contention-based communicationtechnique, rather than a multiple access technique. During the HEcontrol period, the master station 102 may communicate with the HEstations 104 using one or more HE frames. During the HE control period,the HE stations 104 may operate on a channel smaller than the operatingrange of the master station 102. During the HE control period, legacystations refrain from communicating.

In accordance with some embodiments, during the master-synctransmission, the HE stations 104 may contend for the wireless mediumwith the legacy devices 106 being excluded from contending for thewireless medium during the master-sync transmission or TXOP. In someembodiments, the trigger frame may indicate an uplink (UL) UL MU-MIMOand/or a UL OFDMA control period. In some embodiments, the trigger framemay indicate portions of the TXOP that are contention based for some HEstations 104 and portions that are not contention based.

In some embodiments, the multiple access technique used during the HEcontrol period may be a scheduled OFDMA technique, although this is nota requirement. In some embodiments, the multiple access technique may bea time-division multiple access (TDMA) technique or a frequency divisionmultiple access (FDMA) technique. In some embodiments, the multipleaccess technique may be a space-division multiple access (SDMA)technique.

FIG. 2 illustrates a schematic diagram of UL MU transmissions, inaccordance with one or more example embodiments of the presentdisclosure.

Referring to FIG. 2, there is shown an AP 202 in an MU-MIMOcommunication between an AP 202 and four STAs (e.g., STAs 222, 224, 226and 228).

In one embodiment, an enhanced retry count for the UL MU transmissionsystem may include a trigger based UL MU transmission, which may be inaccordance with IEEE 802.11ax. Specifically, the AP 202 may send atrigger frame 204 to trigger data transmission from multiple STAs (e.g.,STAs 222, 224, 226 and 228) simultaneously using OFDMA or MIMO. Itshould be understood that a UL MU transmission is a many to onetransmission capability. For example, the AP 202 may solicitsimultaneous transmission from multiple devices with Wi-Fi capability(e.g., mobile devices, such as phones, tablets, laptops, IoT devicessuch as refrigerators, thermostats, etc.) simultaneously with the UL MUtransmission in accordance with the enhanced retry count for the UL MUtransmission system. In this way, transmissions from multiple STAs canreach the AP efficiently and with fairness to other stations that may becontending to access the communication channel.

It should be understood that in order to accommodate the simultaneoustransmission from multiple STAs, a new physical layer (PHY) format,called HE trigger based PPDU is introduced by IEEE 802.11ax thattriggers an STA to transmit data in response to the trigger frame 204. AQoS design in IEEE 802.11ax includes creating QoS values that arespecific to access categories. In that case, channel access throughcontention involves assigning contention window values that aredependent on the access category in order to provide an advantage forhigher priority frames (e.g., voice versus video).

Currently, for a QoS STA, if after the reception of the trigger frame,the QoS STA attempts to transmit its data to the AP and the transmissionfails, then the QoS STA will update one or more retry counters. Theretry counters may include at least one of a quality of service shortretry counter (QSRC), a quality of service long retry counter (QLRC), aquality of service long drop-eligible retry counter (QLDRC), or aquality of service short drop-eligible retry counter (QSDRC). Each ofthese retry counters is associated with an AC (e.g., QSRC[AC], QLRC[AC],etc.). Consequently, the QoS STA will update, for example, its QSRC[AC]or QLRC[AC] counters if the transmission triggered by the trigger framefrom the AP fails. Each time the QoS STA tries to retransmit thetransmission and a failure occurs, a retry counter is incremented by 1until the counter reaches a threshold. For example, the QoS STAincrements its QSRC every time a transmission of an A-MPDU or a frame ina PSDU of length less than or equal to a threshold fails. According tothe IEEE 802.11 standards, this threshold is designated asdot11RTSThreshold. Further, the QoS STA increments its QLRC every time atransmission of an A-MPDU or a frame in a PSDU of length greater than orequal to dot11RTSThreshold fails.

However, when QSRC[AC] or QLRC[AC] reaches a retry limit, CWmin[AC] willbe set to 0. The retry limit for QSRC is designated asdot11ShortRetryLimit, and the retry limit for the dot11ShortRetryLimitis designated as dot11LongRetryLimit based at least in part on IEEE802.11 standards and may be determined by higher layers. For example, adefault of dot11 ShortRetryLimit may be 7, and the default value ofdot11LongRetryLimit may be 4. Therefore, when the transmissions fail inresponse to the trigger frame from the AP in the UL MU transmissions,after the AP finishes its TXOP, the STA may now have reset a valueassociated with its contention window, CWmin, to be 0, when it contendsfor channel access in the next TXOP or its own single user channelaccess. However, other STAs may have also had transmission failures buthave not reached the limit yet. This will create unfairness between theSTAs that are triggered by the AP for transmission and the STAs that arenot triggered by the AP for transmission because all of the devices thatwere triggered by the AP and experienced transmission failures and thatreached the retry limit will have a shorter contention window to startwith. Therefore, these advantaged STAs will have a shorter channelaccess time and will take precedence over the other STAs. In effect,this may create an unintentional increased priority to devices that weretriggered by the AP in comparison to other STAs.

Typically, a downlink (DL) acknowledgment (e.g., DL ACK 208) may be sentto the one or more STAs involved in the MU-MIMO group duringcommunication between them. The DL acknowledgment indicates to the STAthat the UL response 206 has been received by the AP 202. In case theSTA does not receive a DL acknowledgment, the STA may determine that theUL response has failed to reach the AP 202. Typically, the retrycounters are incremented.

In one embodiment, an STA (e.g., STA 222) may determine to refrain fromupdating its retry counters when the data transmission for thecorresponding AC solicited by the AP through the trigger frame 204fails. It is understood that the above descriptions are for purposes ofillustration and are not meant to be limiting.

FIG. 3 illustrates a schematic diagram of transmission error detectionand a retry counter, in accordance with one or more example embodimentsof the present disclosure.

Referring to FIG. 3, there is shown an STA (e.g., STA 322) that iscontending for channel access in order to transmit to the AP (e.g., AP302). In this case, the STA 322 may have been allocated a TXOP toattempt transmissions to its intended recipient, the AP 302. In thisexample, the STA 322 may be a QoS having a specific AC category assignedto its transmissions (e.g., VO, VI, BE, or BK).

Typically, a QoS STA may transmit on a channel after a channel accessdelay (e.g., channel access delay 304) and while the channel isavailable in order to avoid collisions with existing transmissions. Thechannel access delay may include a backoff counter associated with abackoff window. The backoff window may be based on a contention window(CW) that may be associated with the AC. The five parameters that may beused to determine the backoff window include at least in part aCWmin[AC], a CWmax[AC], a CW[AC], a backoff counter, and a retrycounter. It should be noted that there is a short retry counter and along retry counter for the corresponding AC depending on the length ofthe transmission. For simplicity, the following procedure shows how theretry counter is used. Initially, the CW[AC] is set to CWmin[AC], andthe retry counter is set to zero. When the STA 322 wants to attempt atransmission (e.g., transmission 306), the AP 302 may determine abackoff counter where the backoff counter is randomly drawn from anyvalue between zero and CW. The value of the backoff counter representsthe number of slots that an STA needs to sense that the medium (e.g.,communication channel) is idle before sending its transmission 306. Ifthe transmission 306 fails, the respective retry counter is incrementedby 1. In that case, the process repeats where the STA 322 attemptsanother transmission 310 after a channel access delay 308 and byretrying another random backoff counter value.

However, if the retry counter does not hit the limit, the CW[AC] isupdated as follows: if CW[AC] is less than CWmax[AC], CW[AC] is set tothe value (CW[AC]+1)×2−1. If CW[AC] is equal to CWmax[AC], CW[AC] isleft unchanged.

Again, the process repeats where the STA 322 attempts anothertransmission 310, after a channel access delay 308, and by redrawinganother random backoff counter value. In the example of FIG. 3, the STA322 may detect that the transmission 310 failed because it did notreceive an acknowledgment from the AP 302. In this case, the STA 322 mayupdate its retry counter, which may have reached the retry limit. Whenthe retry counter hits the limit, then the CW[AC] is reset to CWmin[AC],and the retry counter is set to 0. Therefore, when the STA 322 attemptsanother transmission 314, the STA 322 may have a shorter backoff windowbecause the CW[AC] has been reset to CWmin[AC]. Therefore, the STA 322will have a shorter channel access time (e.g., channel access delay 312)during the next channel access attempt and will take precedence overother STAs. In effect, this may create an unintentional increase inpriority to STAs that were triggered by the AP and had transmissionfailures.

FIG. 4 illustrates a schematic diagram of an enhanced retry count for aUL MU transmission system, in accordance with one or more exampleembodiments of the present disclosure.

Referring to FIG. 4, there is shown an AP 402 that may be in an MU-MIMOcommunication with two STAs (e.g., STAs 422 and 424) in an MU-MIMOgroup. STAs 426 and 428 may not be included in that MU-MIMO group. TheAP 402 may send a trigger frame 404 to STAs 422 and 424 solicitingresponses. The trigger frame 404 may include information indicating tothe STAs to send any UL responses (e.g., UL responses 406 and 408) andmay include information associated with the TXOP assigned to the AP 402.

In the example of FIG. 4, it is assumed that the four STAs have hadtransmission failures and that they have reached a retry counter valuethat is close to the limit. For example, in order to illustrate theeffect of hitting the retry counter limit, it is assumed that the fourSTAs have a QLRC[AC]=retry limit−1. That is one more transmissionfailure by any of these STAs will result in their respective counter toreach the retry limit.

In one embodiment, the STA 422 and the STA 424 may detect an error intheir respective transmissions of UL responses 406 and 408. This meansthat the retry counters of the STA 422 and the STA 424 will hit theretry limit. Typically, as explained above, when the retry counterassociated with an STA hits the limit, the CW[AC] is reset to CWmin[AC],the retry counter (e.g., QLRC) is reset to zero, and a new backoffwindow is determined based on these new values. This makes the backoffwindow smaller than the other backoff windows of other STAs making itunfair for the other STAs (e.g., unsolicited STAs). With reference toFIG. 4, if that was the case then the STAs 422 and 424 may have anadvantage for hitting the retry limit when the error was detected. Thisis because the STA 422 and the STA 424, at the end of the TXOP of theAP, may be intended for the channel with a shorter backoff window thanthe STAs 426 and 428, which were not solicited by the trigger frame 404from the AP 402 during the MU-MIMO communication.

In one embodiment, an enhanced retry count for the UL MU transmissionsystem may facilitate, that is if an HE STA does not successfullyreceive the corresponding acknowledgment frame in response to the MPDUsent in an HE trigger based PPDU, the short retry counters and the longretry counters for the associated EDCAF are not incremented or changed.That is, the enhanced retry count for the UL MU transmission system mayrestrict the STAs that are solicited by a trigger frame for datatransmission from updating QSRC[AC] or QLRC[AC] so that CWmin[AC] willnot be updated due to a failure that happened in the TXOP initiated bythe AP to solicit the UL MU transmission. This restriction may preventthe STA from updating CWmin earlier than the STAs that are not solicitedby the trigger frame for transmission. For example, the STAs 422 and 424may be restricted from incrementing their retry counters, which in thiscase are close to the retry limit, when an error condition is detectedafter their respective UL response (e.g., UL responses 406 or 408).Consequently, when the STA 422 and/or the STA 424 detects an error, theywill refrain from updating their respective retry counters during theTXOP allocated to the AP 402. This will result in the STA 422 and theSTA 424 continuing to contend for the channel after the passage of theTXOP allocated to the AP 402. It should be noted that it is possiblethat only some STAs are IEEE 802.11ax STAs, and other STAs are not IEEE802.11ax STAs. Hence, the IEEE 802.11ax STAs can increase theirrespective retry counters more frequently and therefore can hit theretry limit earlier than the non-IEEE 802.11ax STAs (or STAs notsolicited by the AP during an MU-MIMO communication) with the samemedium condition. As a result, IEEE 802.11ax STAs may update CW to CWminmore often, and this will lead to unfairness to the non-IEEE 802.11axSTAs (or STAs not solicited by the AP during an MU-MIMO communication).

In one embodiment, with regard to a QoS STA, ifdot11RobustAVStreamingImplemented is false, then a QoS STA cannot updateQSRC[AC] or QLRC[AC] when the data transmission for corresponding accesscategories (AC) solicited by the AP through the trigger frame fails. Ifdot11RobustAVStreamingImplemented is true, then a QoS STA cannot updatethe QoS short drop-eligible retry counter (QSDRC)[AC] or the QoS longdrop-eligible retry counter (QLDRC)[AC] when the data transmission forthe corresponding AC solicited by the AP through the trigger framefails.

In example embodiments, in regard to non-QoS STAs, an STA cannot updatethe station short retry count (SSRC) or the station long retry count(SLRC) when the data transmission solicited by the AP through thetrigger frame fails.

In example embodiments, for an MSDU without a block acknowledgmentagreement, an STA can be allowed to update its respective retry countersassociated with each MSDU so that the STA could still drop packets whenthe retry count for each packet is reached. For example, a QoS STA canmaintain a short retry counter and a long retry counter for each MACService Data Unit (MSDU), Aggregated MAC Service Data Unit (A-MSDU), orMAC Management Protocol Data Unit (MMPDU) that belongs to a trafficcategory (TC) that requires acknowledgment. The short retry count for anMSDU or an A-MSDU that is not part of a block acknowledgment agreementor for an MMPDU can be incremented every time transmission of a frame ina PSDU of length less than or equal to dot11RTSThreshold fails for thatMSDU, A-MSDU, or MMPDU. The long retry count for an MSDU or an A-MSDUthat is not part of a block acknowledgment agreement or for an MMPDU canbe incremented every time transmission of an MAC frame in a PSDU oflength greater than dot11RTSThreshold fails for that MSDU, A-MSDU, orMMPDU. Retries for failed transmission attempts can continue until oneor more of the following conditions occurs: (a) the short retry countfor the MSDU, A-MSDU, or MMPDU is equal to dot11ShortRetryLimit; or (b)the long retry count for the MSDU, A-MSDU, or MMPDU is equal todot11LongRetryLimit.

In example embodiments, for an MSDU with a block acknowledgmentagreement, it may not be necessary to consider the individual retrycount because it is subject to the MSDU's lifetime. MSDUs that are sentusing the block acknowledgment mechanism are not subject to retry limitsbut only to the MSDU's lifetime.

FIG. 5 illustrates a flow diagram of an illustrative process 500 for anillustrative enhanced retry count for a UL MU transmission system, inaccordance with one or more example embodiments of the presentdisclosure.

At block 502, a device may identify a trigger frame received from afirst device on a wireless communication channel. For example, a triggerframe may be received from a device, such as an access point (AP) on awireless communication channel. The AP may be in an MU-MIMOcommunication with multiple STAs. The AP may send a trigger frame totrigger data transmission from multiple STAs simultaneously usingorthogonal frequency division multiple access (OFDMA) or MIMO.

At block 504, the device may determine a quality of service counterassociated with an access category. For example, the retry counters maybe at least one of a quality of service short retry counter (QSRC), aquality of service long retry counter (QLRC), a quality of service longdrop-eligible retry counter (QLDRC), or a quality of service shortdrop-eligible retry counter (QSDRC).

At block 506, the device may cause to send a frame to the AP based atleast in part on the trigger frame. However, the frame may fail to reachthe AP due to an error condition such as noise, interference, collision,or any other conditions that may prevent the frame from reaching the AP.The STA would determine the error condition based on a failure toreceive an acknowledgment from the AP after sending the frame to the AP.

At block 508, the device may determine an error condition associatedwith the frame. For example, the device may determine a retry counterlimit, which may be determined based at least in part on the type ofretry counter (e.g., QSRC, QLRC, QLDRC, or QSDRC). For example, theretry limit for QSRC is designated as dot11ShortRetryLimit, and theretry limit for the dot11ShortRetryLimit is designated asdot11LongRetryLimit based at least in part on IEEE 802.11 standards andmay be determined by higher layers. The error condition may beassociated with collisions, noise, or interferences. In that case, noacknowledgment of the frame will be received by the STA, and the STAwill increment its retry counter and increase its CW up to a maximumcontention window (CWmax).

At block 510, the device may refrain from incrementing the quality ofservice counter based on the error condition. For example, the devicemay determine whether a dot11RobustAVStreamingImplemented value is setto true or false. The dot11RobustAVStreamingImplemented value may bedetermined by higher layers. If the dot11RobustAVStreamingImplementedvalue is determined to be false, then an STA may refrain from updatingits retry counters (e.g., QSRC or QLRC) when the data transmission forthe corresponding AC solicited by the AP through the trigger framefails. If dot11RobustAVStreamingImplemented is true, then the STA mayrefrain from updating its retry counters (e.g., QSDRC, or QLDRC) whenthe data transmission for the corresponding AC solicited by the APthrough the trigger frame fails. It is understood that the abovedescriptions are for purposes of illustration and are not meant to belimiting.

FIG. 6 illustrates a flow diagram of an illustrative process 600 for anenhanced retry count for a UL MU transmission system, in accordance withone or more example embodiments of the present disclosure.

At block 602, a device may encode a frame with a quality of servicecounter update value. In an MU-MIMO communication between an AP and oneor more STAs belonging to the same MU-MIMO group, the AP may indicate tothe STAs of the MU-MIMO group to determine how and when to update theirretry counters. For example, the AP may determine a quality of servicecounter update value that indicates to the receiving devices that thesedevices should refrain from updating their quality of service counterswhen a transmission error is detected by these devices.

At block 604, the device may cause to send the frame to one or moredevices belonging to an MU-MIMO group. For example, the AP may send theframe that includes the quality of service counter update value, whichmay be set such that these devices belonging to the MU-MIMO group shouldrefrain from updating their retry counters. When the STAs of the MU-MIMOgroup receive the frame, they may decode or otherwise retrieve theinformation associated with the quality of service counter update value.Based on that value, the receiving STAs may determine to refrain (orincrement) their respective retry counters.

At block 606, the device may cause to send a trigger frame to at leastone of the one or more devices. For example, an STA may determine aretry counter limit, which may be determined based at least in part onthe type of retry counter (e.g., QSRC, QLRC, QLDRC, or QSDRC). Forexample, the retry limit for QSRC is designated as dot11ShortRetryLimit,and the retry limit for the dot11ShortRetryLimit is designated asdot11LongRetryLimit based at least in part on IEEE 802.11 standards andmay be determined by higher layers. The device may determine whether adot11RobustAVStreamingImplemented value is set to true or false. Thedot11RobustAVStreamingImplemented value may be determined by higherlayers. If the dot11RobustAVStreamingImplemented value is determined tobe false, then an STA may refrain from updating its retry counters(e.g., QSRC or QLRC) when the data transmission for the corresponding ACsolicited by the AP through a trigger frame fails. Ifdot11RobustAVStreamingImplemented is true, then the STA may refrain fromupdating its retry counters (e.g., QSDRC, or QLDRC) when the datatransmission for the corresponding AC solicited by the AP through thetrigger frame fails. It is understood that the above descriptions arefor purposes of illustration and are not meant to be limiting.

FIG. 7 shows a functional diagram of an exemplary communication station700 in accordance with some embodiments. In one embodiment, FIG. 7illustrates a functional block diagram of a communication station thatmay be suitable for use as a master station 102 or an HE station 104 ofFIG. 1, in accordance with some embodiments. The communication station700 may also be suitable for use as a handheld device, a mobile device,a cellular telephone, a smartphone, a tablet, a netbook, a wirelessterminal, a laptop computer, a wearable computer device, a femtocell, ahigh data rate (HDR) subscriber station, an access point, an accessterminal, or other personal communication system (PCS) device.

The communication station 700 may include communications circuitry 702and a transceiver 710 for transmitting and receiving signals to and fromother communication stations using one or more antennas 701. Thecommunications circuitry 702 may include circuitry that can operate thephysical layer (PHY) communications and/or media access control (MAC)communications for controlling access to the wireless medium, and/or anyother communications layers for transmitting and receiving signals. Thecommunication station 700 may also include processing circuitry 706 andmemory 708 arranged to perform the operations described herein. In someembodiments, the communications circuitry 702 and the processingcircuitry 706 may be configured to perform operations detailed in FIGS.1-6.

In accordance with some embodiments, the communications circuitry 702may be arranged to contend for a wireless medium and configure frames orpackets for communicating over the wireless medium. The communicationscircuitry 702 may be arranged to transmit and receive signals. Thecommunications circuitry 702 may also include circuitry formodulation/demodulation, upconversion/downconversion, filtering,amplification, etc. In some embodiments, the processing circuitry 706 ofthe communication station 700 may include one or more processors. Inother embodiments, two or more antennas 701 may be coupled to thecommunications circuitry 702 arranged for sending and receiving signals.The memory 708 may store information for configuring the processingcircuitry 706 to perform operations for configuring and transmittingmessage frames and performing the various operations described herein.The memory 708 may include any type of memory, including non-transitorymemory, for storing information in a form readable by a machine (e.g., acomputer). For example, the memory 708 may include a computer-readablestorage device, read-only memory (ROM), random-access memory (RAM),magnetic disk storage media, optical storage media, flash-memory devicesand other storage devices and media.

In some embodiments, the communication station 700 may be part of aportable wireless communication device, such as a personal digitalassistant (PDA), a laptop or portable computer with wirelesscommunication capability, a web tablet, a wireless telephone, asmartphone, a wireless headset, a pager, an instant messaging device, adigital camera, an access point, a television, a medical device (e.g., aheart rate monitor, a blood pressure monitor, etc.), a wearable computerdevice, or another device that may receive and/or transmit informationwirelessly.

In some embodiments, the communication station 700 may include one ormore antennas 701. The antennas 701 may include one or more directionalor omnidirectional antennas, including, for example, dipole antennas,monopole antennas, patch antennas, loop antennas, microstrip antennas,or other types of antennas suitable for transmission of RF signals. Insome embodiments, instead of two or more antennas, a single antenna withmultiple apertures may be used. In these embodiments, each aperture maybe considered a separate antenna. In some multiple-input multiple-output(MIMO) embodiments, the antennas may be effectively separated forspatial diversity and the different channel characteristics that mayresult between each of the antennas and the antennas of a transmittingstation.

In some embodiments, the communication station 700 may include one ormore of a keyboard, a display, a non-volatile memory port, multipleantennas, a graphics processor, an application processor, speakers, andother mobile device elements. The display may be an LCD screen includinga touch screen.

Although the communication station 700 is illustrated as having severalseparate functional elements, two or more of the functional elements maybe combined and may be implemented by combinations ofsoftware-configured elements, such as processing elements includingdigital signal processors (DSPs), and/or other hardware elements. Forexample, some elements may include one or more microprocessors, DSPs,field-programmable gate arrays (FPGAs), application specific integratedcircuits (ASICs), radio-frequency integrated circuits (RFICs) andcombinations of various hardware and logic circuitry for performing atleast the functions described herein. In some embodiments, thefunctional elements of the communication station 700 may refer to one ormore processes operating on one or more processing elements.

Certain embodiments may be implemented in one or a combination ofhardware, firmware, and software. Other embodiments may also beimplemented as instructions stored on a computer-readable storagedevice, which may be read and executed by at least one processor toperform the operations described herein. A computer-readable storagedevice may include any non-transitory memory mechanism for storinginformation in a form readable by a machine (e.g., a computer). Forexample, a computer-readable storage device may include read-only memory(ROM), random-access memory (RAM), magnetic disk storage media, opticalstorage media, flash-memory devices, and other storage devices andmedia. In some embodiments, the communication station 700 may includeone or more processors and may be configured with instructions stored ona computer-readable storage device memory.

FIG. 8 illustrates a block diagram of an example of a machine 800 orsystem upon which any one or more of the techniques (e.g.,methodologies) discussed herein may be performed. In other embodiments,the machine 800 may operate as a standalone device or may be connected(e.g., networked) to other machines. In a networked deployment, themachine 800 may operate in the capacity of a server machine, a clientmachine, or both in server-client network environments. In an example,the machine 800 may act as a peer machine in peer-to-peer (P2P) (orother distributed) network environments. The machine 800 may be Themachine 800 may be a master station 102, HE station 104, a personalcomputer (PC), a tablet PC, a set-top box (STB), a personal digitalassistant (PDA), a mobile telephone, a wearable computer device, a webappliance, a network router, a switch or bridge, or any machine capableof executing instructions (sequential or otherwise) that specify actionsto be taken by that machine, such as a base station. Further, while onlya single machine is illustrated, the term “machine” shall also be takento include any collection of machines that individually or jointlyexecute a set (or multiple sets) of instructions to perform any one ormore of the methodologies discussed herein, such as cloud computing,software as a service (SaaS), or other computer cluster configurations.

Examples, as described herein, may include or may operate on logic or anumber of components, modules, or mechanisms. Modules are tangibleentities (e.g., hardware) capable of performing specified operationswhen operating. A module includes hardware. In an example, the hardwaremay be specifically configured to carry out a specific operation (e.g.,hardwired). In another example, the hardware may include configurableexecution units (e.g., transistors, circuits, etc.) and a computerreadable medium containing instructions where the instructions configurethe execution units to carry out a specific operation when in operation.The configuring may occur under the direction of the executions units ora loading mechanism. Accordingly, the execution units arecommunicatively coupled to the computer-readable medium when the deviceis operating. In this example, the execution units may be a member ofmore than one module. For example, under operation, the execution unitsmay be configured by a first set of instructions to implement a firstmodule at one point in time and reconfigured by a second set ofinstructions to implement a second module at a second point in time.

The machine (e.g., computer system) 800 may include a hardware processor802 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 804 and a static memory 806, some or all of which may communicatewith each other via an interlink (e.g., bus) 808. The machine 800 mayfurther include a power management device 832, a graphics display device810, an alphanumeric input device 812 (e.g., a keyboard), and a userinterface (UI) navigation device 814 (e.g., a mouse). In an example, thegraphics display device 810, alphanumeric input device 812, and UInavigation device 814 may be a touch screen display. The machine 800 mayadditionally include a storage device (i.e., drive unit) 816, a signalgeneration device 818 (e.g., a speaker), an enhanced retry count for ULMU transmission device 819, a network interface device/transceiver 820coupled to antenna(s) 830, and one or more sensors 828, such as a globalpositioning system (GPS) sensor, a compass, an accelerometer, or othersensor. The machine 800 may include an output controller 834, such as aserial (e.g., universal serial bus (USB), parallel, or other wired orwireless (e.g., infrared (IR), near field communication (NFC), etc.)connection to communicate with or control one or more peripheral devices(e.g., a printer, a card reader, etc.)).

The storage device 816 may include a machine readable medium 822 onwhich is stored one or more sets of data structures or instructions 824(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 824 may alsoreside, completely or at least partially, within the main memory 804,within the static memory 806, or within the hardware processor 802during execution thereof by the machine 800. In an example, one or anycombination of the hardware processor 802, the main memory 804, thestatic memory 806, or the storage device 816 may constitutemachine-readable media.

The enhanced retry count for UL MU transmission device 819 may carry outor perform any of the operations and processes (e.g., processes 500 and600) described and shown above. For example, the enhanced retry countfor UL MU transmission device 819 may identify a trigger frame receivedfrom a device, such as an AP on a wireless communication channel. The APmay be in an MU-MIMO communication with multiple STAs. The AP may send atrigger frame to trigger data transmission from multiple STAssimultaneously using OFDMA or MIMO.

The enhanced retry count for UL MU transmission device 819 may cause tosend a frame to the AP based at least in part on the trigger frame.However, the frame may fail to reach the AP due to an error conditionsuch as noise, interference, collision, or any other conditions that mayprevent the frame from reaching the AP. The STA would determine theerror condition based on a failure to receive an acknowledgment from theAP after sending the frame to the AP.

The enhanced retry count for UL MU transmission device 819 may determinethe retry counters to be at least one of a quality of service shortretry counter (QSRC), a quality of service long retry counter (QLRC), aquality of service long drop-eligible retry counter (QLDRC), or aquality of service short drop-eligible retry counter (QSDRC).

The enhanced retry count for UL MU transmission device 819 may determinea retry counter limit, which may be determined based at least in part onthe type of retry counter (e.g., QSRC, QLRC, QLDRC, or QSDRC). Forexample, the retry limit for QSRC is designated as dot11ShortRetryLimit,and the retry limit for the dot11ShortRetryLimit is designated asdot11LongRetryLimit based at least in part on IEEE 802.11 standards andmay be determined by higher layers.

The enhanced retry count for UL MU transmission device 819 may determinewhether a dot11RobustAVStreamingImplemented value is set to true orfalse. The dot11RobustAVStreamingImplemented value may be determined byhigher layers. If the dot11RobustAVStreamingImplemented value isdetermined to be false, then an STA may refrain from updating its retrycounters (e.g., QSRC or QLRC) when the data transmission for thecorresponding AC solicited by the AP through the trigger frame fails. Ifdot11RobustAVStreamingImplemented is true, then the STA may refrain fromupdating its retry counters (e.g., QSDRC, or QLDRC) when the datatransmission for the corresponding AC solicited by the AP through atrigger frame fails. It is understood that the above descriptions arefor purposes of illustration and are not meant to be limiting.

It is understood that the above are only a subset of what the enhancedretry count for UL MU transmission device 819 may be configured toperform and that other functions included throughout this disclosure mayalso be performed by the enhanced retry count for UL MU transmissiondevice 819.

While the machine-readable medium 822 is illustrated as a single medium,the term “machine-readable medium” may include a single medium ormultiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 824.

Various embodiments may be implemented fully or partially in softwareand/or firmware. This software and/or firmware may take the form ofinstructions contained in or on a non-transitory computer-readablestorage medium. Those instructions may then be read and executed by oneor more processors to enable performance of the operations describedherein. The instructions may be in any suitable form, such as but notlimited to source code, compiled code, interpreted code, executablecode, static code, dynamic code, and the like. Such a computer-readablemedium may include any tangible non-transitory medium for storinginformation in a form readable by one or more computers, such as but notlimited to read only memory (ROM); random access memory (RAM); magneticdisk storage media; optical storage media; a flash memory, etc.

The term “machine-readable medium” may include any medium that iscapable of storing, encoding, or carrying instructions for execution bythe machine 800 and that cause the machine 800 to perform any one ormore of the techniques of the present disclosure, or that is capable ofstoring, encoding, or carrying data structures used by or associatedwith such instructions. Non-limiting machine-readable medium examplesmay include solid-state memories and optical and magnetic media. In anexample, a massed machine-readable medium includes a machine-readablemedium with a plurality of particles having resting mass. Specificexamples of massed machine-readable media may include non-volatilememory, such as semiconductor memory devices (e.g., electricallyprogrammable read-only memory (EPROM), or electrically erasableprogrammable read-only memory (EEPROM)) and flash memory devices;magnetic disks, such as internal hard disks and removable disks;magneto-optical disks; and CD-ROM and DVD-ROM disks.

The instructions 824 may further be transmitted or received over acommunications network 826 using a transmission medium via the networkinterface device/transceiver 820 utilizing any one of a number oftransfer protocols (e.g., frame relay, internet protocol (IP),transmission control protocol (TCP), user datagram protocol (UDP),hypertext transfer protocol (HTTP), etc.). Example communicationsnetworks may include a local area network (LAN), a wide area network(WAN), a packet data network (e.g., the Internet), mobile telephonenetworks (e.g., cellular networks), plain old telephone (POTS) networks,wireless data networks (e.g., Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 family of standards known as Wi-Fi®, IEEE 802.16family of standards known as WiMax®), IEEE 802.15.4 family of standards,and peer-to-peer (P2P) networks, among others. In an example, thenetwork interface device/transceiver 820 may include one or morephysical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or moreantennas to connect to the communications network 826. In an example,the network interface device/transceiver 820 may include a plurality ofantennas to wirelessly communicate using at least one of single-inputmultiple-output (SIMO), multiple-input multiple-output (MIMO), ormultiple-input single-output (MISO) techniques. The term “transmissionmedium” shall be taken to include any intangible medium that is capableof storing, encoding, or carrying instructions for execution by themachine 800 and includes digital or analog communications signals orother intangible media to facilitate communication of such software. Theoperations and processes described and shown above may be carried out orperformed in any suitable order as desired in various implementations.Additionally, in certain implementations, at least a portion of theoperations may be carried out in parallel. Furthermore, in certainimplementations, less than or more than the operations described may beperformed.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. The terms “computing device,” “userdevice,” “communication station,” “station,” “handheld device,” “mobiledevice,” “wireless device” and “user equipment” (UE) as used hereinrefers to a wireless communication device such as a cellular telephone,a smartphone, a tablet, a netbook, a wireless terminal, a laptopcomputer, a femtocell, a high data rate (HDR) subscriber station, anaccess point, a printer, a point of sale device, an access terminal, orother personal communication system (PCS) device. The device may beeither mobile or stationary.

As used within this document, the term “communicate” is intended toinclude transmitting, or receiving, or both transmitting and receiving.This may be particularly useful in claims when describing theorganization of data that is being transmitted by one device andreceived by another, but only the functionality of one of those devicesis required to infringe the claim. Similarly, the bidirectional exchangeof data between two devices (both devices transmit and receive duringthe exchange) may be described as “communicating,” when only thefunctionality of one of those devices is being claimed. The term“communicating” as used herein with respect to a wireless communicationsignal includes transmitting the wireless communication signal and/orreceiving the wireless communication signal. For example, a wirelesscommunication unit, which is capable of communicating a wirelesscommunication signal, may include a wireless transmitter to transmit thewireless communication signal to at least one other wirelesscommunication unit, and/or a wireless communication receiver to receivethe wireless communication signal from at least one other wirelesscommunication unit.

As used herein, unless otherwise specified, the use of the ordinaladjectives “first,” “second,” “third,” etc., to describe a commonobject, merely indicates that different instances of like objects arebeing referred to and are not intended to imply that the objects sodescribed must be in a given sequence, either temporally, spatially, inranking, or in any other manner.

The term “access point” (AP) as used herein may be a fixed station. Anaccess point may also be referred to as an access node, a base station,or some other similar terminology known in the art. An access terminalmay also be called a mobile station, user equipment (UE), a wirelesscommunication device, or some other similar terminology known in theart. Embodiments disclosed herein generally pertain to wirelessnetworks. Some embodiments may relate to wireless networks that operatein accordance with one of the IEEE 802.11 standards.

Some embodiments may be used in conjunction with various devices andsystems, for example, a personal computer (PC), a desktop computer, amobile computer, a laptop computer, a notebook computer, a tabletcomputer, a server computer, a handheld computer, a handheld device, apersonal digital assistant (PDA) device, a handheld PDA device, anon-board device, an off-board device, a hybrid device, a vehiculardevice, a non-vehicular device, a mobile or portable device, a consumerdevice, a non-mobile or non-portable device, a wireless communicationstation, a wireless communication device, a wireless access point (AP),a wired or wireless router, a wired or wireless modem, a video device,an audio device, an audio-video (A/V) device, a wired or wirelessnetwork, a wireless area network, a wireless video area network (WVAN),a local area network (LAN), a wireless LAN (WLAN), a personal areanetwork (PAN), a wireless PAN (WPAN), and the like.

Some embodiments may be used in conjunction with one way and/or two-wayradio communication systems, cellular radio-telephone communicationsystems, a mobile phone, a cellular telephone, a wireless telephone, apersonal communication system (PCS) device, a PDA device whichincorporates a wireless communication device, a mobile or portableglobal positioning system (GPS) device, a device which incorporates aGPS receiver or transceiver or chip, a device which incorporates an RFIDelement or chip, a multiple input multiple output (MIMO) transceiver ordevice, a single input multiple output (SIMO) transceiver or device, amultiple input single output (MISO) transceiver or device, a devicehaving one or more internal antennas and/or external antennas, digitalvideo broadcast (DVB) devices or systems, multi-standard radio devicesor systems, a wired or wireless handheld device, e.g., a smartphone, awireless application protocol (WAP) device, or the like.

Some embodiments may be used in conjunction with one or more types ofwireless communication signals and/or systems following one or morewireless communication protocols, for example, radio frequency (RF),infrared (IR), frequency-division multiplexing (FDM), orthogonal FDM(OFDM), time-division multiplexing (TDM), time-division multiple access(TDMA), extended TDMA (E-TDMA), general packet radio service (GPRS),extended GPRS, code-division multiple access (CDMA), wideband CDMA(WCDMA), CDMA 2000, single-carrier CDMA, multi-carrier CDMA,multi-carrier modulation (MDM), discrete multi-tone (DMT), Bluetooth®,global positioning system (GPS), Wi-Fi, Wi-Max, ZigBee, ultra-wideband(UWB), global system for mobile communications (GSM), 2G, 2.5G, 3G,3.5G, 4G, fifth generation (5G) mobile networks, 3GPP, long termevolution (LTE), LTE advanced, enhanced data rates for GSM Evolution(EDGE), or the like. Other embodiments may be used in various otherdevices, systems, and/or networks.

According to example embodiments of the disclosure, there may be adevice. The device may include memory and processing circuitryconfigured to identify a trigger frame received from a first device on awireless communication channel. The memory and processing circuitry maybe further configured to determine a quality of service counterassociated with an access category. The memory and processing circuitrymay be further configured to cause to send a frame to the first devicebased at least in part on the trigger frame. The memory and processingcircuitry may be further configured to determine an error conditionassociated with the frame. The memory and processing circuitry may befurther configured to refrain from incrementing the quality of servicecounter based on the error condition.

The implementations may include one or more of the following features.The error condition may include a failure to receive an acknowledgmentfrom the first device after causing to send the frame. The trigger frameis associated with a transmission duration. The quality of servicecounter is at least one of a quality of service short retry counter(QSRC), a quality of service long retry counter (QLRC), a quality ofservice long drop-eligible retry counter (QLDRC), or a quality ofservice short drop-eligible retry counter (QSDRC). The memory and theprocessing circuitry may be further configured to determine apredetermined value is set to false, wherein the quality of servicecounter is a quality of service short retry counter (QSRC) or a qualityof service long retry counter (QLRC). The memory and processingcircuitry may be further configured to refrain from incrementing thequality of service counter. The memory and the processing circuitry maybe further configured to determine a predetermined value is set to true,wherein the quality of service counter is a quality of service shortdrop-eligible retry counter (QSDRC) or a quality of service longdrop-eligible retry counter (QLDRC). The memory and processing circuitrymay be further configured to refrain from incrementing the quality ofservice counter. The access category is at least one of a voicecategory, a video category, a best effort category, or a backgroundcategory. The memory and the processing circuitry may be furtherconfigured to cause to delay sending the frame on the wirelesscommunication channel by a time delay based at least in part on abackoff window. The backoff window is based on a contention windowassociated with the access category. The device may further include atransceiver configured to transmit and receive wireless signals. Thedevice may further include one or more antennas coupled to thetransceiver.

According to example embodiments of the disclosure, there may be adevice. The device may include memory and processing circuitryconfigured to encode a frame with a quality of service counter updatevalue. The memory and processing circuitry may be further configured tocause to send the frame to one or more devices belonging to a multiusermultiple input and multiple output (MU-MIMO) group. The memory andprocessing circuitry may be further configured to cause to send atrigger frame to at least one of the one or more devices.

The implementations may include one or more of the following features.The memory and the processing circuitry may be further configured todetermine an error condition associated with at least one data framefrom the at least one of the one or more devices. The quality of servicecounter update value indicates to the at least one of the one or moredevices to refrain from updating its quality of service counter when atransmission error is detected by the at least one of the one or moredevices. The quality of service counter is at least one of a quality ofservice short retry counter (QSRC), a quality of service long retrycounter (QLRC), a quality of service long drop-eligible retry counter(QLDRC), or a quality of service short drop-eligible retry counter(QSDRC).

According to example embodiments of the disclosure, there may be anon-transitory computer-readable medium storing computer-executableinstructions which, when executed by a processor, cause the processor toperform operations. The operations may include encoding a frame with aquality of service counter update value. The operations may includecausing to send the frame to one or more devices belonging to amultiuser multiple input and multiple output (MU-MIMO) group. Theoperations may include causing to send a trigger frame to at least oneof the one or more devices.

The implementations may include one or more of the following features.The operations further may include determining an error conditionassociated with at least one data frame from the at least one of the oneor more devices. The quality of service counter update value indicatesto the at least one of the one or more devices to refrain from updatingits quality of service counter when a transmission error is detected bythe at least one of the one or more devices. The quality of servicecounter is at least one of a quality of service short retry counter(QSRC), a quality of service long retry counter (QLRC), a quality ofservice long drop-eligible retry counter (QLDRC), or a quality ofservice short drop-eligible retry counter (QSDRC).

According to example embodiments of the disclosure, there may be anon-transitory computer-readable medium storing computer-executableinstructions which, when executed by a processor, cause the processor toperform operations. The operations may include identifying, by one ormore processors, a trigger frame received from a first device on awireless communication channel. The operations may include determining aquality of service counter associated with an access category. Theoperations may include causing to send a frame to the first device basedat least in part on the trigger frame. The operations may includedetermining an error condition associated with the frame. The operationsmay include refraining from incrementing the quality of service counterbased on the error condition.

The implementations may include one or more of the following features.The error condition may include a failure to receive an acknowledgmentfrom the first device after causing to send the frame. The quality ofservice counter is at least one of a quality of service short retrycounter (QSRC), a quality of service long retry counter (QLRC), aquality of service long drop-eligible retry counter (QLDRC), or aquality of service short drop-eligible retry counter (QSDRC). Theoperations may include determining a predetermined value is set tofalse, wherein the quality of service counter is a quality of serviceshort retry counter (QSRC) or a quality of service long retry counter(QLRC). The operations may include refraining from incrementing thequality of service counter. The operations may include determining apredetermined value is set to true, wherein the quality of servicecounter is a quality of service short drop-eligible retry counter(QSDRC) or a quality of service long drop-eligible retry counter(QLDRC). The operations may include refraining from incrementing thequality of service counter. The access category is at least one of avoice category, a video category, a best effort category, or abackground category. The operations may include causing to delay sendingthe frame on the wireless communication channel by a time delay based atleast in part on a backoff window. The backoff window is based on acontention window associated with the access category.

According to example embodiments of the disclosure, there may include amethod. The method may include identifying, by one or more processors, atrigger frame received from a first device on a wireless communicationchannel. The method may include determining a quality of service counterassociated with an access category. The method may include causing tosend a frame to the first device based at least in part on the triggerframe. The method may include determining an error condition associatedwith the frame. The method may include refraining from incrementing thequality of service counter based on the error condition.

The implementations may include one or more of the following features.The error condition includes a failure to receive an acknowledgment fromthe first device after causing to send the frame. The quality of servicecounter is at least one of a quality of service short retry counter(QSRC), a quality of service long retry counter (QLRC), a quality ofservice long drop-eligible retry counter (QLDRC), or a quality ofservice short drop-eligible retry counter (QSDRC). The method mayfurther include determining a predetermined value is set to false,wherein the quality of service counter is a quality of service shortretry counter (QSRC) or a quality of service long retry counter (QLRC).The method may include refraining from incrementing the quality ofservice counter. The method may further include determining apredetermined value is set to true, wherein the quality of servicecounter is a quality of service short drop-eligible retry counter(QSDRC) or a quality of service long drop-eligible retry counter(QLDRC). The method may include refraining from incrementing the qualityof service counter. The access category is at least one of a voicecategory, a video category, a best effort category, or a backgroundcategory. The method may further include causing to delay sending theframe on the wireless communication channel by a time delay based atleast in part on a backoff window. The backoff window is based on acontention window associated with the access category.

According to example embodiments of the disclosure, there may include amethod. The method may include encoding a frame with a quality ofservice counter update value. The method may include causing to send theframe to one or more devices belonging to a multiuser multiple input andmultiple output (MU-MIMO) group. The method may include causing to senda trigger frame to at least one of the one or more devices. Theimplementations may include one or more of the following features. Themethod may further include determining an error condition associatedwith at least one data frame from the at least one of the one or moredevices. The quality of service counter update value indicates to the atleast one of the one or more devices to refrain from updating itsquality of service counter when a transmission error is detected by theat least one of the one or more devices. The quality of service counteris at least one of a quality of service short retry counter (QSRC), aquality of service long retry counter (QLRC), a quality of service longdrop-eligible retry counter (QLDRC), or a quality of service shortdrop-eligible retry counter (QSDRC).

In example embodiments of the disclosure, there may be an apparatus. Theapparatus may include means for identifying, by one or more processors,a trigger frame received from a first device on a wireless communicationchannel. The apparatus may include means for determining a quality ofservice counter associated with an access category. The apparatus mayinclude means for causing to send a frame to the first device based atleast in part on the trigger frame. The apparatus may include means fordetermining an error condition associated with the frame. The apparatusmay include means for refraining from incrementing the quality ofservice counter based on the error condition.

The implementations may include one or more of the following features.The error condition includes a failure to receive an acknowledgment fromthe first device after causing to send the frame. The quality of servicecounter is at least one of a quality of service short retry counter(QSRC), a quality of service long retry counter (QLRC), a quality ofservice long drop-eligible retry counter (QLDRC), or a quality ofservice short drop-eligible retry counter (QSDRC). The apparatus mayfurther include means for determining a predetermined value is set tofalse, wherein the quality of service counter is a quality of serviceshort retry counter (QSRC) or a quality of service long retry counter(QLRC). The apparatus may further include means for refraining fromincrementing the quality of service counter. The apparatus may furtherinclude means for determining a predetermined value is set to true,wherein the quality of service counter is a quality of service shortdrop-eligible retry counter (QSDRC) or a quality of service longdrop-eligible retry counter (QLDRC). The apparatus may further includemeans for refraining from incrementing the quality of service counter.The access category is at least one of a voice category, a videocategory, a best effort category, or a background category. Theapparatus may further include means for causing to delay sending theframe on the wireless communication channel by a time delay based atleast in part on a backoff window. The backoff window is based on acontention window associated with the access category.

An apparatus may further include encoding a frame with a quality ofservice counter update value. The apparatus may further include causingto send the frame to one or more devices belonging to a multiusermultiple input and multiple output (MU-MIMO) group. The apparatus mayfurther include causing to send a trigger frame to at least one of theone or more devices.

The implementations may include one or more of the following features.The operations may further include determining an error conditionassociated with at least one data frame from the at least one of the oneor more devices. The quality of service counter update value indicatesto the at least one of the one or more devices to refrain from updatingits quality of service counter when a transmission error is detected bythe at least one of the one or more devices. The quality of servicecounter is at least one of a quality of service short retry counter(QSRC), a quality of service long retry counter (QLRC), a quality ofservice long drop-eligible retry counter (QLDRC), or a quality ofservice short drop-eligible retry counter (QSDRC).

Certain aspects of the disclosure are described above with reference toblock and flow diagrams of systems, methods, apparatuses, and/orcomputer program products according to various implementations. It willbe understood that one or more blocks of the block diagrams and flowdiagrams, and combinations of blocks in the block diagrams and the flowdiagrams, respectively, may be implemented by computer-executableprogram instructions. Likewise, some blocks of the block diagrams andflow diagrams may not necessarily need to be performed in the orderpresented, or may not necessarily need to be performed at all, accordingto some implementations.

These computer-executable program instructions may be loaded onto aspecial-purpose computer or other particular machine, a processor, orother programmable data processing apparatus to produce a particularmachine, such that the instructions that execute on the computer,processor, or other programmable data processing apparatus create meansfor implementing one or more functions specified in the flow diagramblock or blocks. These computer program instructions may also be storedin a computer-readable storage media or memory that may direct acomputer or other programmable data processing apparatus to function ina particular manner, such that the instructions stored in thecomputer-readable storage media produce an article of manufactureincluding instruction means that implement one or more functionsspecified in the flow diagram block or blocks. As an example, certainimplementations may provide for a computer program product, comprising acomputer-readable storage medium having a computer-readable program codeor program instructions implemented therein, said computer-readableprogram code adapted to be executed to implement one or more functionsspecified in the flow diagram block or blocks. The computer programinstructions may also be loaded onto a computer or other programmabledata processing apparatus to cause a series of operational elements orsteps to be performed on the computer or other programmable apparatus toproduce a computer-implemented process such that the instructions thatexecute on the computer or other programmable apparatus provide elementsor steps for implementing the functions specified in the flow diagramblock or blocks.

Accordingly, blocks of the block diagrams and flow diagrams supportcombinations of means for performing the specified functions,combinations of elements or steps for performing the specified functionsand program instruction means for performing the specified functions. Itwill also be understood that each block of the block diagrams and flowdiagrams, and combinations of blocks in the block diagrams and flowdiagrams, may be implemented by special-purpose, hardware-based computersystems that perform the specified functions, elements or steps, orcombinations of special-purpose hardware and computer instructions.

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainimplementations could include, while other implementations do notinclude, certain features, elements, and/or operations. Thus, suchconditional language is not generally intended to imply that features,elements, and/or operations are in any way required for one or moreimplementations or that one or more implementations necessarily includelogic for deciding, with or without user input or prompting, whetherthese features, elements, and/or operations are included or are to beperformed in any particular implementation.

Many modifications and other implementations of the disclosure set forthherein will be apparent having the benefit of the teachings presented inthe foregoing descriptions and the associated drawings. Therefore, it isto be understood that the disclosure is not to be limited to thespecific implementations disclosed and that modifications and otherimplementations are intended to be included within the scope of theappended claims. Although specific terms are employed herein, they areused in a generic and descriptive sense only and not for purposes oflimitation.

What is claimed is:
 1. A device, the device comprising memory andprocessing circuitry configured to: identify a trigger frame receivedfrom a first device on a wireless communication channel; determine aquality of service counter associated with an access category; cause tosend a frame to the first device based at least in part on the triggerframe; determine an error condition associated with the frame; andrefrain from incrementing the quality of service counter based on theerror condition.
 2. The device of claim 1, wherein the error conditionincludes a failure to receive an acknowledgment from the first deviceafter causing to send the frame.
 3. The device of claim 1, wherein thetrigger frame is associated with a transmission duration.
 4. The deviceof claim 1, wherein the quality of service counter is at least one of aquality of service short retry counter (QSRC), a quality of service longretry counter (QLRC), a quality of service long drop-eligible retrycounter (QLDRC), or a quality of service short drop-eligible retrycounter (QSDRC).
 5. The device of claim 2, wherein the memory and theprocessing circuitry are further configured to: determine apredetermined value is set to false, wherein the quality of servicecounter is a quality of service short retry counter (QSRC) or a qualityof service long retry counter (QLRC); and refrain from incrementing thequality of service counter.
 6. The device of claim 2, wherein the memoryand the processing circuitry are further configured to: determine apredetermined value is set to true, wherein the quality of servicecounter is a quality of service short drop-eligible retry counter(QSDRC) or a quality of service long drop-eligible retry counter(QLDRC); and refrain from incrementing the quality of service counter.7. The device of claim 1, wherein the access category is at least one ofa voice category, a video category, a best effort category, or abackground category.
 8. The device of claim 1, wherein the memory andthe processing circuitry are further configured to cause to delaysending the frame on the wireless communication channel by a time delaybased at least in part on a backoff window.
 9. The device of claim 8,wherein the backoff window is based on a contention window associatedwith the access category.
 10. The device of claim 1, further comprisinga transceiver configured to transmit and receive wireless signals. 11.The device of claim 9, further comprising one or more antennas coupledto the transceiver.
 12. A non-transitory computer-readable mediumstoring computer-executable instructions which when executed by one ormore processors result in performing operations comprising: encoding aframe with a quality of service counter update value; causing to sendthe frame to one or more devices belonging to a multi-usermultiple-input and multiple-output (MU-MIMO) group; and causing to senda trigger frame to at least one of the one or more devices.
 13. Thenon-transitory computer-readable medium of claim 12, wherein theoperations further comprise determining an error condition associatedwith at least one data frame from the at least one of the one or moredevices.
 14. The non-transitory computer-readable medium of claim 12,wherein the quality of service counter update value indicates to the atleast one of the one or more devices to refrain from updating itsquality of service counter when a transmission error is detected by theat least one of the one or more devices.
 15. The non-transitorycomputer-readable medium of claim 14, wherein the quality of servicecounter is at least one of a quality of service short retry counter(QSRC), a quality of service long retry counter (QLRC), a quality ofservice long drop-eligible retry counter (QLDRC), or a quality ofservice short drop-eligible retry counter (QSDRC).
 16. A methodcomprising: identifying, by one or more processors, a trigger framereceived from a first device on a wireless communication channel;determining a quality of service counter associated with an accesscategory; causing to send a frame to the first device based at least inpart on the trigger frame; determining an error condition associatedwith the frame; and refraining from incrementing the quality of servicecounter based on the error condition.
 17. The method of claim 16,wherein the error condition includes a failure to receive anacknowledgment from the first device after causing to send the frame.18. The method of claim 16, wherein the quality of service counter is atleast one of a quality of service short retry counter (QSRC), a qualityof service long retry counter (QLRC), a quality of service longdrop-eligible retry counter (QLDRC), or a quality of service shortdrop-eligible retry counter (QSDRC).
 19. The method of claim 16, furthercomprising: determining a predetermined value is set to false, whereinthe quality of service counter is a quality of service short retrycounter (QSRC) or a quality of service long retry counter (QLRC); andrefraining from incrementing the quality of service counter.
 20. Themethod of claim 16, further comprising: determining a predeterminedvalue is set to true, wherein the quality of service counter is aquality of service short drop-eligible retry counter (QSDRC) or aquality of service long drop-eligible retry counter (QLDRC); andrefraining from incrementing the quality of service counter.